Tuesday 30 June 2015

Hyper-V Virtualization 101: Hardware Considerations

When we deploy a Hyper-V virtualization solution we look at:
  1. VM IOPS Requirements
  2. VM vRAM Requirements
  3. VM vCPU Requirements
In that order.

Disk Subsystem

The disk subsystem tends to be the first bottleneck.
For a solution with dual E5-2600 series CPUs and 128GB of RAM requiring 16 VMs or thereabouts we'd be at 16 to 24 10K SAS drives at the minimum for this setup with a 1GB hardware RAID controller (non-volatile or battery backed cache).
RAID 6 is our go-to for array configuration.
Depending on workloads one can look at Intel's DC S3500 series SSDs or the higher endurance DC S3700 series models to get more IOPS out of the disk subsystem.


Keep in mind that the physical RAM is split between the two processors so one needs to be mindful of how the vRAM is divvied up between the VMs.
Too much vRAM on one or two VMs can cause the physical RAM to be juggled between the two physical CPUs (NUMA).
Note that each VM’s vRAM gets a file written to disk. So, if we are allocating 125GB of vRAM to the VMs there will be 125GB of files on disk.


And finally, each vCPU within a VM represents a thread to the physical CPU. For VMs with multiple vCPUs every thread (vCPU) for that VM needs to be processed by the CPU's pipeline in parallel. So, the more vCPUs we assign to a VM the more the CPU's logic needs to juggle the threads to have them processed.
The end result? More vCPUs is not always better.
I have an Experts Exchange article on Some Hyper-V Hardware and Software Best Practices that should be of some assistance too. In it I speak about the need to tweak the BIOS settings on the server, hardware configurations to eliminate single point of failures (SPFs), and more.


In the end, it is up to us to make sure we test out our configurations before we deploy them. Having a high five figure SAN installed to solve certain performance “issues” only to find out they exist _after_ the fact can be a very bad place to be in.
We test all aspects of a standalone and clustered system to discover its strengths and weaknesses. While this can be a very expensive policy, to date we’ve not had one performance issue with our deployments.
Our testing can also be quite beneficial to present an IOPS and throughput reports based on sixteen different allocation sizes (hardware and software) to our client _and_ the vendor complaining about our system. ;)
Philip Elder
Microsoft Cluster MVP
Co-Author: SBS 2008 Blueprint Book

Wednesday 17 June 2015

What's up, what's been happing, and what will be happening.

Wow, it's been a while hasn't it? :)

We've been _very_ busy with our business as well as a Cloud services start-up and Third Tier is keeping me hopping too.

I have a regular monthly Webinar via Third Tier where we've been spending time on the Third Tier product called "Be the Cloud". It is a solution set developed to provide a highly available backend for client facing services based on our SBS (Small Business Solution).

We, that is my family, took a much needed break in May for a couple of weeks of downtime as we'd not had any pause for a good 18 months prior. We were ready for that.

So, why the blogging pause?

There are a number of reasons.

One is that I've been so busy researching and working on new things that there hasn't been a lot of time left over for writing them all out. Ongoing client needs are obviously a part of that too.

Another had to do with waiting until we were okay to publish information on the upcoming Windows Server release. We Cluster MVPs, and others, were privileged to be very deeply involved with the early stages of the new product. But, we were required to remain mum. So, instead of risking anything I decided to hold off on publishing anything Server vNext related.

Plus, we really didn't have a lot of new content to post since we've about covered the gamut in Windows Server 2012 RTM/R2 and Windows Desktop. Things have been stable on that front other than a few patch related bumps in the road. So, nothing new there meant nothing new to write about. ;)

And finally, the old grey matter just needed a break. After all, I've been writing on this blog since the beginning of 2007! :)

So, what does this mean going forward?

It means that we will begin publishing content on a regular basis again once we've began serious work with Windows Server vNext.

We have a whole host of lab hardware on the way that has a lot to do with what's happening in the new version of Windows Server that ties into our v2 for Be the Cloud and our own Cloud services backend.

We're also establishing some new key vendor relationships that will broaden our solution matrix with some really neat new features. As always, we build our solution sets and test them vigorously before considering a sale to a client.

And finally, we're reworking our PowerShell library into a nice and tidy OneNote notebook set to help us keep consistent across the board. This is quite time consuming as it becomes readily apparent that many steps are in the grey matter but not in Notepad or OneNote.

Things we're really excited about:
  • Storage Spaces Direct (S2D)
  • Storage Replication
  • Getting the Start Menu back for RDSH Deployments
    • Our first deployment on TP2 is going to happen soon so hopefully we do indeed have control over that feature again!
  • Deploying our first TP2 RDS Farm
  • Intel Server Systems are on the S2D approval list!
    • The Intel Server System R2224WTTYS is an excellent platform
  • Promise Storage J5000 series JBODs just got on the Storage Spaces approved list.
    • We've had a long history with Promise and are looking forward to re-establishing that relationship.
  • We've started working with Mellanox for assistance with RDMA Direct and RoCE.
  • 12Gb SAS in HBAs and JBODs rocks for storage
    • 2 Node SOFS Cluster with JBOD is 96Gbps of aggregate ultra-low latency SAS bandwidth per node!
  • NVMe based storage (PCIe direct)
The list could go on and on as they come to mind. :)

Thank you all for your patience with the lack of posting lately. And, thank you all for your feedback and support over the years. It has been a privilege to get to know some of you and work with some of you as well.

We are most certainly looking forward to the many things we have coming down the pipe. 2015 is shaping up to be our best year ever with 2016 looking to build on that!

Philip Elder
Microsoft Cluster MVP
Co-Author: SBS 2008 Blueprint Book